Experimental Investigation of Heat-Treated Aluminum Profiles

2015 ◽  
Vol 651-653 ◽  
pp. 59-64
Author(s):  
Marion Merklein ◽  
Matthias Graser ◽  
Michael Lechner
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Experimental Investigation ◽  
Material Flow ◽  
Material Characterization ◽  
Process Window ◽  
Short Term ◽  
Property Distribution ◽  
Heat Treated ◽  
Aluminum Profiles

Tailor Heat Treated Profiles (THTP) are profiles that exhibit local different mechanical properties optimized for a subsequent forming operation. The property distribution is realized by short term heat treatment before a forming operation. Based on the interaction of soft and hard areas the material flow can be improved and the formability can be enhanced. Prerequisite for a successful application of the technology is a comprehensive material characterization. Therefore, within this paper the influence of short term heat treatment on the mechanical properties of profiles will be presented. In particular, different heating technologies based on heat conduction and laser radiation are compared. Based on the results, a process window will be derived. All investigations were performed using the precipitation hardenable aluminum alloy EN AW 6060.

Application of Tailored Heat Treated Blanks under Quasi Series Conditions

2007 ◽  
Vol 344 ◽  
pp. 383-390 ◽  
Author(s):  
Marion Merklein ◽  
Uwe Vogt
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Local Heat ◽  
Strength Distribution ◽  
Process Window ◽  
Short Term ◽  
Forming Process ◽  
Heat Treated ◽  
Set Up ◽  
The Impact

Tailored Heat Treated Blanks (THTB) are blanks that exhibit locally different strength specifically optimized for the succeeding forming process. The strength distribution is set by a local, short-term heat treatment modifying the mechanical properties of the material. Hence, THTB allow enhancing forming limits significantly leading to shorter and more robust manufacture process chains. In order to qualify the use of THTB under quasi series conditions, the interdependencies of the blank’s local heat treatment and the entire process chain of the car body manufacture have to be analyzed. In this respect, the impact of a short-term heat treatment on the mechanical properties of AA6181PX, a commonly used aluminum alloy in today’s car bodies, was studied. Also the influence of a short-term heat treatment on the coil lubricant, usually already applied by the material supplier, was given a closer look. Based on these experiments process restrictions for the application of THTB in an industrial automotive environment were derived and a process window for the THTB design was set up. In conclusion, strategies were defined how to enhance the found process boundaries leading to a more robust process window.

Precipitation Behaviour and Mechanical Properties during Short-Term Heat Treatment for Tailor Heat Treated Profiles (THTP) of Aluminium Alloy 6060 T4

2016 ◽  
Vol 877 ◽  
pp. 400-406 ◽  
Author(s):  
Hannes Fröck ◽  
Matthias Graser ◽  
Benjamin Milkereit ◽  
Michael Reich ◽  
Michael Lechner ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminium Alloy ◽  
Heat Treatments ◽  
Maximum Temperature ◽  
Short Term ◽  
Scanning Calorimetry ◽  
Heat Treated ◽  
Precipitation Behaviour ◽  
Dissolution And Precipitation

Precipitation hardening aluminium alloys are widely used for automotive applications. To enhance the application of aluminium profiles, improved formability is needed. Tailor Heat Treated Profiles (THTP) with locally different material properties attempt to increase formability e.g. in bending processes. Tailoring of local properties is obtained by a local short-term heat treatment, dissolving the initial precipitate state (retrogression) and still allowing subsequent ageing. In the present study, the dissolution and precipitation behaviour of the aluminium alloy EN AW-6060 T4 was investigated during heating with differential scanning calorimetry (DSC). Heating curves from 20 to 600 °C with heating rates of 0.01 up to 5 K/s were recorded. Interrupted heat treatments with different maximum temperatures were performed in a deformation dilatometer. Immediately afterwards, tensile tests were carried out at room temperature. The course of the recorded mechanical properties as a function of the maximum temperature is discussed with regard to the dissolution and precipitation behaviour during heating. Finally, the aging behaviour of the investigated alloy was recorded after different typical short-term heat treatments and is discussed with reference to the DSC‐curves. The correlation of the microstructure and the mechanical properties enables the derivation of optimal parameters for the development of THTP through a local softening.

Comprehensive Material Characterization for an Intermediate Heat Treatment

2013 ◽  
Vol 549 ◽  
pp. 39-44 ◽  
Author(s):  
Michael Lechner ◽  
Andreas Kuppert ◽  
Marion Merklein
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
New Technologies ◽  
Process Window ◽  
Short Term ◽  
Intermediate Heat Treatment ◽  
Comprehensive Knowledge ◽  
New Strategy ◽  
Two Parameters ◽  
The Impact

Encouraged by increasing climate regulations there is a trend to lightweight constructions in the transportation sector, particularly in the automotive industry. An auspicious possibility to reduce the weight of the vehicle is the substitution of conventional steel by aluminum alloys. However, aluminum has a low formability and therefore new technologies have to be found in order to enhance the materials spectrum of application. A new strategy to extend the process limit is the short-term aluminum intermediate heat treatment between two forming operations. Key idea is the partial adaption of the mechanical properties with a short term heat treatment. By the interaction of soft and hard areas the material flow during the forming operation can be improved and the formability can be enhanced. Prerequisite for a successful application of the technology and the numerical simulation is a comprehensive knowledge about the interaction of pre-straining and a subsequent short term heat treatment. Within this paper the mechanical properties in dependency of the two parameters will be presented and a process window for the heat treatment after first forming operations will be derived. Moreover, the influence of batch fluctuations and the impact of ageing will be demonstrated.

Tailored Heat Treated Profiles - Enhancement of the Forming Limit of Aluminum Profiles under Bending Load

2012 ◽  
Vol 504-506 ◽  
pp. 375-380 ◽  
Author(s):  
Marion Merklein ◽  
Michael Lechner ◽  
Thomas Schneider ◽  
Raoul Plettke
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Tests ◽  
Local Heat ◽  
Forming Limit ◽  
Cold Bending ◽  
Heat Treated ◽  
Bending Load ◽  
Local Modification ◽  
Aluminum Profiles

Aluminum profiles are well-established components in lightweight constructions. However, these profiles have a small forming capability in comparison to steel profiles, which leads to a limitation in their application. Within this paper a new and innovative approach for the enhancement of the forming limit of aluminum profiles under bending load called Tailored Heat Treated Profiles (THTP) is presented. With THTP the mechanical properties of the material are locally modified by a short-term heat treatment. By this local modification the material flow during the following cold bending operation can be influenced. For the design of the heat treatment layout, the correlation between the heat treatment parameters and the material properties has to be investigated. Tensile specimens were cut out of the profile and were subsequently completely heat treated with a laser. The changes of the mechanical properties caused by the heat treatment were analyzed by tensile tests. However, with a complete softening of the profile, the formability could not be improved. To increase the formability a local heat treatment, which leads to partial softening of the profile, has to be investigated. In order to characterize the heat-affected zone (HAZ) of the laser treatment, thermal camera and microhardness measurements were carried out. Appropriate heat treatment layouts have to be found to enhance the forming limit. Different layout strategies were developed and afterwards validated by the heat treatment and forming of profiles. This paper will present the findings of this investigation and show that THTP can be used to improve the formability of aluminum profiles for bending operations.

scholarly journals Influence of Short-Term Heat Treatment on the Mechanical Properties of Al–Mg–Si Profiles

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 664 ◽  
Author(s):  
Sandra Kernebeck ◽  
Sebastian Weber
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Automotive Industry ◽  
Measurement Method ◽  
Natural Aging ◽  
Hot Extrusion ◽  
Tensile Tests ◽  
Short Term ◽  
Aluminum Profiles

Aluminum profiles—for instance, profiles made of precipitation-hardenable alloys—are increasingly used for decorative details in the automotive industry. Typically, after hot extrusion and at least two to three days of natural aging (NA), the aluminum profiles are artificially aged. A commercial EN AW-6060 alloy of high purity was used for this investigation. Tensile tests were used as the main measurement method. This article focuses on the effect of short-term heat treatment on the point in time at which a significant increase of the ultimate tensile strength (UTS) during NA can be measured. Short-term heat treatment is shown to delay this point in time by almost four days, but it increases the variation of UTS. A heterogeneous temperature profile during short-term heat treatment was identified as one reason for this result. Finally, a strategy for minimizing variations in mechanical properties of artificially-aged aluminum alloys was developed, based on the experimental results of this study.

Adjusting Optimized Material Properties for Tailored Heat Treated Blanks

2011 ◽  
Vol 473 ◽  
pp. 420-427
Author(s):  
Marion Merklein ◽  
Hung Nguyen
Keyword(s):  
Heat Treatment ◽  
Aluminum Alloys ◽  
Material Properties ◽  
Precipitation Hardening ◽  
Process Window ◽  
Sheet Metals ◽  
Lightweight Construction ◽  
Short Term ◽  
Conductive Heating ◽  
Heat Treated

Aluminum alloys have great potential for lightweight construction. In order to achieve an optimized properties distribution for the forming operation and to enhance the formability of aluminum alloys, so called Tailored Heat Treated Blanks (THTB) are developed. In this context, this paper is about the local precipitation hardening of sheet metals for the application of THTB. By using a specific, short-term heat treatment via conductive heating plates the thermal induced hardening of the fast hardenable alloy AA6181PX is quantified and qualified. Considering the processibility of the local precipitation hardening for THTB, a process window for the heat treatment parameters is presented allowing a precise setting of the mechanical material properties.

Investigation of the Portevin-Le Chatelier Effect in AlMgSi-Tailored Heat Treated Blanks

2015 ◽  
Vol 639 ◽  
pp. 123-130 ◽  
Author(s):  
Alexander Kahrimanidis ◽  
Daniel Wortberg ◽  
Marion Merklein
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Critical Strain ◽  
Influence Factors ◽  
High Demand ◽  
Short Term ◽  
Heat Treated ◽  
Critical Strain Rate ◽  
Potential Applications ◽  
Chatelier Effect

The dissolution of co-clusters in AlMgSi-alloys by a short term heat treatment can be used to locally adjust the mechanical properties of a blank for a following forming operation. This approach is known as Tailored Heat Treated Blanks (THTB) and allows to significant enhance the forming limits of AlMgSi-alloys. However, the dissolution of co-clusters leads to the observation of the Portevin-Le Chatelier (PLC) effect during deformation. The results are stretcher strain marks at the surface which are a limitation for potential applications of THTB. In contrast to AlMg-alloys, a critical strain rate above which no PLC effect occurs is not observed for the investigated alloys. This paper investigates various influence factors on the occurrence of the PLC effect for different AlMgSi-alloys and presents an approach under which conditions THTB can be used in applications with high demand on surface quality.

scholarly journals Influence of Post Weld Heat Treatment on the Grain Size, and Mechanical Properties of the Alloy-800H Rotary Friction Weld Joints

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4366
Author(s):  
Saqib Anwar ◽  
Ateekh Ur Rehman ◽  
Yusuf Usmani ◽  
Ali M. Al-Samhan
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Grain Size ◽  
Heat Affected Zone ◽  
Tensile Testing ◽  
Weld Zone ◽  
Alloy 800H ◽  
Weld Joints ◽  
Heat Treated ◽  
Friction Weld

This study evaluated the microstructure, grain size, and mechanical properties of the alloy 800H rotary friction welds in as-welded and post-weld heat-treated conditions. The standards for the alloy 800H not only specify the composition and mechanical properties but also the minimum grain sizes. This is because these alloys are mostly used in creep resisting applications. The dynamic recrystallization of the highly strained and plasticized material during friction welding resulted in the fine grain structure (20 ± 2 µm) in the weld zone. However, a small increase in grain size was observed in the heat-affected zone of the weldment with a slight decrease in hardness compared to the base metal. Post-weld solution heat treatment (PWHT) of the friction weld joints increased the grain size (42 ± 4 µm) in the weld zone. Both as-welded and post-weld solution heat-treated friction weld joints failed in the heat-affected zone during the room temperature tensile testing and showed a lower yield strength and ultimate tensile strength than the base metal. A fracture analysis of the failed tensile samples revealed ductile fracture features. However, in high-temperature tensile testing, post-weld solution heat-treated joints exhibited superior elongation and strength compared to the as-welded joints due to the increase in the grain size of the weld metal. It was demonstrated in this study that the minimum grain size requirement of the alloy 800H friction weld joints could be successfully met by PWHT with improved strength and elongation, especially at high temperatures.

Effect of heat treatment on mechanical properties of 3D printed polylactic acid parts

2021 ◽  
Vol 63 (1) ◽  
pp. 73-78
Author(s):  
Pulkin Gupta ◽  
Sudha Kumari ◽  
Abhishek Gupta ◽  
Ankit Kumar Sinha ◽  
Prashant Jindal
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Polylactic Acid ◽  
Recrystallization Temperature ◽  
Fused Deposition Modelling ◽  
Fused Deposition ◽  
Dog Bone ◽  
Heat Treated ◽  
Maximum Decrease ◽  
3D Printed

Abstract Fused deposition modelling (FDM) is a layer-by-layer manufacturing process type of 3D-printing (3DP). Significant variation in the mechanical properties of 3D printed specimens is observed because of varied process parameters and interfacial bonding between consecutive layers. This study investigates the influence of heat treatment on the mechanical strength of FDM 3D printed Polylactic acid (PLA) parts with constant 3DP parameters and ambient conditions. To meet the objectives, 7 sets, each containing 5 dog-bone shaped samples, were fabricated from commercially available PLA filament. Each set was subjected to heat treatment at a particular temperature for 1 h and cooled in the furnace itself, while one set was left un-treated. The temperature for heat treatment (Th) varied from 30 °C to 130 °C with increments of 10 °C. The heat-treated samples were characterized under tensile loading of 400 N and mechanical properties like Young’s modulus (E), Strain % ( ε ) and Stiffness (k) were evaluated. On comparing the mechanical properties of heat-treated samples to un-treated samples, significant improvements were observed. Heat treatment also altered the geometries of the samples. Mechanical properties improved by 4.88 % to 10.26 % with the maximum being at Th of 110 °C and below recrystallization temperature (Tr) of 65 °C. Deformations also decreased significantly at higher temperatures above 100 °C, by a maximum of 36.06 %. The dimensions of samples showed a maximum decrease of 1.08 % in Tr range and a maximum decrease of 0.31 % in weight at the same temperature. This study aims to benefit the society by establishing suitable Th to recover the lost strength in PLA based FDM 3D printed parts.

Influence of Heat Treatment on Microstrudture and Mechanical Properties of AZ31B Magnesium Alloy Prepared by Solid-State Recycling

2012 ◽  
Vol 271-272 ◽  
pp. 17-20
Author(s):  
Shu Yan Wu ◽  
Ze Sheng Ji ◽  
Chun Ying Tian ◽  
Ming Zhong Wu
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Solid State ◽  
Magnesium Alloy ◽  
Static Recrystallization ◽  
Annealing Treatment ◽  
Az31b Magnesium Alloy ◽  
Heat Treated ◽  
Elongation To Failure ◽  
Strength And Ductility

This work is to study the influence of heat treatment on microstrudture and mechanical properties of AZ31B magnesium alloy prepared by solid -state recycling. AZ31B magnesium alloy chips were recycled by hot extruding. Three different heat treatments were conducted for recycled alloy. Mechanical properties and microstructure of the recycled specimen and heat treated specimen were investigated. 300°C×2h annealing specimen exhibits finer grain due to static recrystallization, and microstructure of 400°C×2h annealing specimen becomes more coarse. 300°C×2h annealing treatment improves obviously strength and ductility of recycled alloy. Ultimate tensile strength of alloy decreases and elongation to failure increases after 400°C×2h annealing. Grain size, dislocation density and bonding of chips have an effect on the elongation of recycled materials. 190°C×8h ageing has no influence on microstructure and mechanical properties of recycled alloy.

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